In the discussion of liberty, I believe an oft overlooked aspect is what I would call the "capacity for enforcement". Sure, an ancient king could have you executed for speaking against him, but he would have to hear it or have someone report it to him that did. Our laws today may be less draconian, but with a modern police force, surveillance, forensics, etc everything is much more enforceable. Even back in like the 1920s, it would be unrealistic for the government to reliably enforce a law say, limiting the capacity of a boat engine. Now to do such is fairly easy, using a modern policing force and monitoring tactics/algorithms. It is because of this that I believe man is less free than he has ever been.